Mountain sickness is an illness that ranges from a mild headache and weariness to a life-threatening build-up of fluid in the lungs (pulmonary edema) at high altitudes. Mountain climbers try to avoid mountain sickness by climbing higher in the daytime, then descending to sleep lower. In this way they get accustomed to the difference in pressure and in oxygen-density.

In this chapter Itachi will make an appearance and he is, in many aspects, different from the anime - my plot simply wouldn't work otherwise. Therefore let me introduce him to you, to show a glimpse of his motives and emotions.

On a superficial level Itachi is not really hostile. He just categorizes people: most will be neutral, as long as they don't threat him or his cause. To them, he may appear as any young introverted man. For him communication is a tool, has a function thus if he has nothing to say, he doesn't talk; if he wants to say something, he does. His way of speaking is functional, too: say what you want with the most accurate sentence.

In the deep inside however he's not as composed as he looks. He didn't simply loose everything, he had to be the cause of it. To be devoted to his role, but to hate it at the same time; this contradiction fights inside him. In a twisted way it's similar to when you know, that what you're about to say will hurt the other, but you feel you have to do it (the end justifies the means). This way of thinking made him evil; but at the same time preserved part of his innocence.

Art by shybyakugangirl.devianart.com

Itachi's views on fate was inspired by Stoic philosophy, namely causal determinism. According to the Stoics all events throughout the course of history are connected to antecedent events that cause them, and that they in turn are themselves antecedent causes of what must follow after. In other words there never has been and there never will be even a single event that is not caused. Everything is how it is because it has been determined to be like that by prior circumstances that caused it.

Such words as 'random' or 'accidental' are only given names for causes, that has not yet been discovered. 'Probability' also exist only in case when we don't know the causes. Therefore when we say 'there is a probability that this and that will happen' means that we are not aware of the cause-consequence chains behind the events. In case we were aware of them, we would know for sure what is going to happen.

Courier ninjas a greately underrated, yet actually they have the only independent ninja organization that has an its own City-State, a beautiful monastery built on a mountain in the Land of Birds. The organization is called Hikyaku Ninja no Soshiki or Courier Ninja Organization - or simply CNO. People generally call them postmen or mailmen, which they find highly degrading, since they consider themselves monks: CNO has its own esoteric philosophy, they have their own jutsu system as well as their own ninja school, and on the contrary of general belief it's not easy to become a courier ninja: one must undertake years of practice and meditation in order to become an active member.

In order to learn more about the origin of their organization let's take a look at their name written by kanjis:

飛脚忍者の組織

The first two kanjis 飛脚 are pronounced as hikyaku and means 'courier'. The first kanji of courier means 'to fly', while the second kanji means 'leg'. Indeed, just like Hermes in Greek or Mercury in Roman mythology, the World of Naruto has its own Messenger of Gods, who founded the organization and the courier ninja profession according to their legends.

I'd like to show you something interesting. Please look at the third-fourth kanji 忍者 which means 'ninja'. The original word for ninja was shinbi-no-mono  忍の者. Shinobu means 'to conceal, spy, sneak' and the kanji for mono means 'person'. Thus ninja came from the different reading of the same kanji.

Now, Naruto wants to become a Hokage because he wants to get people acknowledge him as a great ninja, right? The word for 'admit' is mitomeru in Japanese, and is written by the following kanji: 認 If you look at it closely you can see that the right side of the kanji looks like this: 言 which means 'to say', while the right side of the kanji is the kanji of shinobi! That is exactly what Naruto wants, to make people admit that he's a good ninja, in other words to acknowledge him! Isn't it as if the legend of Naruto takes shape behind this kanji?

When the heart breaks we also die with it a little bit.. and although we can come back to life and mend the broken heart, it gets harder and harder each time. It's better not to find out whether we have nine lives like cats or not...
In Chapter 2 Sakura tells us about the times her heart was broken, though I didn't (want to) list all of them.